Sheryl Crow, Guster, Dave Matthews Launch Green Music Group

What do Sheryl Crow, Guster, the Barenaked Ladies, Willie Nelson and the Dave Matthews Band have in common? They're all founding members of the new Green Music Group, a coalition of musicians and fans committed to environmental action.

The GMG just launched, and as an incentive to get you to join, they are offering a free download of a new song from the members of Maroon 5, The Roots, Dave Matthews Band and Guster. The single, "Sunday," was recorded in a jam session at a GMG event on January 30 and is definitely iPod worthy.

Also, if you opt-in, you'll be entered to win one of three autographed eco-friendly guitars: a Gibson Les Paul Smartwood, a Martin Sustainable Wood acoustic, or a First Act Bambusa.

But what's really the point of signing up? The Green Music Group is still in the development stages but will get rolling in a few weeks. They'll eventually start asking fans to take part in a series of environmental challenges. Anyone who completes the challenges can quality to win free concert tickets, guitars, bikes and a whole lot more.

Signing up is easy, and it's a fun way to spread eco-positive messages. Give it a try and see what comes next. Maybe a carbon-neutral society.

Photo by Haags Uitburo, via Flickr.